Product Description
Underbody Mounting Kits: Bolt Any Underbody Box Straight to Your Truck or Trailer Deck. Made in the USA by AMERICAN TRUCKBOXES ATB®️
This underbody side mounting kit is built for contractors and fleet operators who hang toolboxes off the bottom of a truck or trailer deck. It gives you a secure, deck-mounted point for hanging your box without cutting into the frame. This kit is manufactured by American Truckboxes LLC in Blanchard, North Dakota.
Key Features
- Bolts straight to the deck: two 3/16 inch aluminum mounting brackets hang the box from the underside of the deck, no frame modification required
- Secure connection at every point: nine Grade 8 bolts per bracket for eighteen high-strength bolts across the kit
- Everything you need in one box: ships complete with two mounting brackets, Grade 8 bolts, washers, nuts, and an installation sheet
- Built for tie-down winch setups: designed for decks where tie-down winches are already in place, working around your existing hardware
- Corrosion-resistant material: 3/16 inch aluminum stands up to road salt and moisture without rusting through
- Two kit lengths: Standard (6 inch) kit type for shorter drop distances and Extended (12 inch) kit type when the box hangs further from the deck
- Four depth options: sized to fit 18, 20, 22, or 24 inch depth underbody boxes so bracket spacing lines up with your box
- Grade 8 hardware throughout: every bolt is rated for the vibration and load an underbody box sees on the road
Specifications
Material: 3/16 inch aluminum | Kit Type: Standard (6 inch) or Extended (12 inch) | Box Depth: 18, 20, 22, or 24 inch | Weight: 15 to 18 lbs depending on size | Warranty: 60-month limited (standard), 12-month limited (custom/modified)
Made in the USA for over 25 years, American Truckboxes builds every mounting kit to hold up under real jobsite use. Visit truckbox.com or call (888) 996-0376 for custom sizing.
Frequently Asked Questions
Q: Where is this underbody mounting kit made?
A: This kit is made in the USA by American Truckboxes LLC in Blanchard, North Dakota. American Truckboxes has manufactured truck toolboxes and mounting hardware for over 25 years. Full product details are available at truckbox.com.
Q: What warranty comes with this mounting kit?
A: Standard kits carry a 60-month (5-year) limited warranty. Custom or modified kits and auxiliary fuel tank hardware carry a 12-month limited warranty. The warranty applies to the original purchaser only and is non-transferable. Call (888) 996-0376 or visit truckbox.com for full warranty details.
Q: Can I order a custom size?
A: Yes, custom sizes are available beyond the standard 18, 20, 22, and 24 inch depth options listed here. Custom and modified kits carry a 12-month warranty. Contact American Truckboxes at truckbox.com or (888) 996-0376 to discuss a custom fit.
Q: What is the difference between the Standard and Extended kit type?
A: The Standard (6 inch) kit type is built for a shorter drop from the deck, while the Extended (12 inch) kit type hangs the box further down from the deck. Choose the kit type that matches how far your underbody box needs to sit below the deck rail.
Q: How does this kit attach to my truck or trailer?
A: Two 3/16 inch aluminum mounting brackets bolt to the underside of the deck using nine Grade 8 bolts per bracket, eighteen bolts total. No frame drilling is required beyond the mounting points, and the kit ships with all bolts, washers, and nuts included.
Q: Will this kit work with a deck that already has tie-down winches installed?
A: Yes, this mounting kit is designed for decks where tie-down winches are already in place, so it works around that existing hardware rather than requiring you to remove it.
Q: What size underbody box does this kit fit?
A: This kit is available in four depth sizes: 18, 20, 22, and 24 inch, so you can match the bracket spacing to your specific underbody box depth. Select the depth option that corresponds to your box when ordering.